This invention relates to a device disposed between a doffer and a crushing roll pair of a carding machine which treats cotton fiber, chemical fiber or the like. The device has an element which is stationarily disposed underneath a stripper roll which removes fiber material as a fiber web from a doffer. The upper surface of the element is oriented towards a region of the stripper roll and a terminal region of the element is situated in the zone between the doffer and the stripper roll.
In a known device the stationary element extends from the doffer to the middle of the stripper roll. The zone between the middle of the stripper roll and the downstream-arranged, superposed crushing rolls is downwardly open. The thin web which is separated at that region by the stripping roll from the doffer runs through a free space until it reaches the nip defined between the two crushing rolls. Upon an increase of the output speed of the card, that is, an increase, for example, to 300 m/min or above, the air stream flowing rearwardly from the crushing rolls interferes with the web travel. The air stream, particularly that which flows rearwardly from the nip between the crushing rolls eventually reaches such a high rearward speed that the unsupported, freely running fiber web is blown back in certain regions. Since the upper crushing roll is close to the stripping roll, the air entrained by the stripping roll may bound back from the upper crushing roll and may also have an adverse effect on the fiber web. The rearwardly directed air streams may press downwardly the thin fiber web, resulting in sagging and tear. Thus, at high delivery speeds the uniform material advance is adversely affected.